Spanish tummy vs constipation

Spanish tummy

constipation

noun
  • The act of crowding anything into a lesser space, or the state of being crowded or pressed together; condensation. 

  • A state of the bowels in which the evacuations are infrequent and difficult, or the intestines become filled with hardened faeces 

How often have the words Spanish tummy and constipation occurred in a corpus of books? (source: Google Ngram Viewer )